2011 09 11 – ISS Lunar Transit
I drove to Leander, TX, this morning to catch the ISS lunar transit. This is the field sketch, mirrored and rotated to match standard orientation.
Equipment: 102mm f/9.8 refractor on an LXD75, 16mm eyepiece, 13% transmission Moon filter; Sketch media: black Strathmore Artagain paper, white pastels, white charcoal, black charcoal
The sketch was a quickie compared to the phase sketches I typically do, but I wanted to ensure the ISS wouldn’t be lost in the detail. The ISS crossed the lunar face in less than half a second, starting near the craters Steinheil and Watt. It then passed near Encke before crossing the NW limb.
I re-familiarized myself with the guidelines from Alan Strauss’ ISS solar transit observation in 2011. You can view the report and sketch on his site, Lost Pleiad Observatory.
Before leaving the house, I rechecked the ISS flight path and its central line for passing in front of the Moon. CalSky is a great program for this. On my iPhone, I used GoSatWatch and set alerts for 5 minutes before the pass and another for when the pass began.
The sketch was started almost an hour before the pass. So that the ISS wouldn’t be lost within the abundance of lunar terrain, the majority of detail was omitted from the sketch. Once the first alert went off, I stopped sketching and prepared myself for the pass. My observing partner, Freckles (my dog), was put back in the CRV so that I could focus solely on the view. The transit would last only a fraction of a second and in that time, I wanted to note: where it entered, the flight path, and where it excited; color and luminance; shape, size and orientation; and viewable panels and modules.
The second alert sounded and within moments, the ISS made its transit. I was surprised to see that it was a glowing white color (expected a silhouette) and what appeared to be a shadow on one side of it. It seems I may have caught a module and one of the solar arrays. The shadow was most likely another solar array or the shadowed area of the module. As for the orientation, it was offset a little from its path, but things happened so suddenly that I’m not certain I’ve recorded it accurately. My focus was more on the overall shape and the shadow of the ISS.
With each ISS pass, it’s an ongoing endeavor to improve my observing and sketching skills for the next time!
PCW Memorial Observatory - Erika Rix 